Chapter 30 contains the national ambient air quality standards (NAAQS) for the specific criteria pollutants set out in 40 CFR Part 50. Incorporation of the NAAQS into the state regulations is necessary to provide a legally enforceable means by which the state prepares attainment and maintenance plans, and determines whether a new source will affect the NAAQS. The standard for lead was revised to add a new standard of 0.15 parts per million (ppm).